Physiological Studies on the Effects of Silicic Acid upon Rice Plants : IX. Effects of silicic acid on the growth of rice plant under high and low temperature of culture solution

Abstract

The growth of rice plants grown under high temperature "35-36°C" (H), low temperature "21±1°C" (L) and control "31±1°C (C) of cultur solution supplied with (S) and without=(N) silicic acid were compared with each other. The results obtained are as follows : 1. The growth of rice plants of N was inferior to that of S, and under the high temperature the dry weight of rice plants of N was especially small. 2. The amount of silicic acid adsorbed by the rice plants of SL was smaller than that of SH, and that of SC was larger than those of SL and SH. 3. The amounts of nitrogen, phosphorus and potassium absorbed by the rice plant of NH, especially the amounts of these elements in panicle were comparatively smaller. The amounts of nitrogen and potassium absorbed by the rice plants of LN were smaller than those of CN, but the amount of phosphorus absorbed by the former was larger than that of absorbed by the letter. The accumulated amounts of these three elements in the panicle of rice plants of N were respectively smaller than those of S. The contents of total sugar in the rice plants of NH and SH were smaller than those of C, but those of L were lager than those of C. The contents of starch in rice plant of S were lager than those of N in three treatments. The difference (ratio) of starch content between S and N was especially lager in H. 4. The growth of rice plant raised without silicic acid under the high temperature of cultur solution was considerably poor. As to treatment L, the growth amounts of S and N were a little smaller than that of control, respectively. Under the high temperatur of culture solution the growth of rice plant was poor, but the growth of rice plant grown under the low temperature was only a little poorer than that of control. It was recognized from the above mentioned facts that silicic acid ameliolates the growth retardation of rice plant grown under the high or low temperature.